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I have an analog sensor which features 3 wires: power supply +, ground (common for supply and signal output) and signal output iself. Sensor is working in industrial environment. I am using shielded cable. Know that only one end should be connected but the question is where - common signal ground or protective earth (PE/mains earth)? The power supply for sensor will be isolated one. I suppose in industrial environment we would like to protect from power equipment capacitively coupled noise assuming that common plane in this type of environment is the mains PE. Does this make any sense?

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  • \$\begingroup\$ You should use 4 internal wires that are shielded. It's called shielded star-quad cable. That is the way to transport a signal from a sensor that is powered where one of the sensors connections is also common to signal. \$\endgroup\$
    – Andy aka
    Commented Dec 30, 2021 at 20:29
  • \$\begingroup\$ Yes, but the shield has to be connected somewhere. So what is the best option in industrial environment - PE or common analog signal ground? \$\endgroup\$
    – XgN
    Commented Dec 30, 2021 at 21:37
  • \$\begingroup\$ I connect the shield to earth one end only. \$\endgroup\$
    – Gil
    Commented Dec 30, 2021 at 21:51
  • \$\begingroup\$ Please link the cable you are planning on using. \$\endgroup\$
    – Andy aka
    Commented Dec 30, 2021 at 22:39
  • \$\begingroup\$ It will be shielded either flat or round ribbon cable for IDC connector. 16 channels in toltal where each output signal has signal ground in the parallel conductor. \$\endgroup\$
    – XgN
    Commented Dec 31, 2021 at 9:06

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The wiring is to be carried out as shown below.

enter image description here

The shield is to be connected to earth ground, only at the analog input end.

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  • \$\begingroup\$ Thank you, had the same question but can you explain why it should be connected to earth ground and not signal ground? \$\endgroup\$
    – divB
    Commented yesterday

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